Re: [PATCH v1 9/9] diff --color-moved-ws: handle blank lines

Phillip Wood <phillip.wood@xxxxxxxxxxxx> · Wed, 21 Nov 2018 15:49:56 +0000

On 20/11/2018 18:05, Stefan Beller wrote:
On Fri, Nov 16, 2018 at 3:04 AM Phillip Wood <phillip.wood@xxxxxxxxxxxx> wrote:

From: Phillip Wood <phillip.wood@xxxxxxxxxxxxx>

When using --color-moved-ws=allow-indentation-change allow lines with
the same indentation change to be grouped across blank lines. For now
this only works if the blank lines have been moved as well, not for
blocks that have just had their indentation changed.

This completes the changes to the implementation of
--color-moved=allow-indentation-change. Running

   git diff --color-moved=allow-indentation-change v2.18.0 v2.19.0

now takes 5.0s. This is a saving of 41% from 8.5s for the optimized
version of the previous implementation and 66% from the original which
took 14.6s.

Signed-off-by: Phillip Wood <phillip.wood@xxxxxxxxxxxxx>
---

Notes:
     Changes since rfc:
      - Split these changes into a separate commit.
      - Detect blank lines when processing the indentation rather than
        parsing each line twice.
      - Tweaked the test to make it harder as suggested by Stefan.
      - Added timing data to the commit message.

  diff.c                     | 34 ++++++++++++++++++++++++++++---
  t/t4015-diff-whitespace.sh | 41 ++++++++++++++++++++++++++++++++++----
  2 files changed, 68 insertions(+), 7 deletions(-)

diff --git a/diff.c b/diff.c
index 89559293e7..072b5bced6 100644
--- a/diff.c
+++ b/diff.c
@@ -792,9 +792,11 @@ static void moved_block_clear(struct moved_block *b)
         memset(b, 0, sizeof(*b));
  }

+#define INDENT_BLANKLINE INT_MIN

Answering my question from the previous patch:
This is why we need to keep the indents signed.

This patch looks quite nice to read along.

The whole series looks good to me.

Thanks

Do we need to update the docs in any way?

I'm not sure, at the moment it does not make any promises about the 
exact behavior of --color-moved-ws=allow-indentation-change, we could 
change it to be more explicit but I'm not sure it's worth it.

Thanks for looking over these patches, I'll post a reroll soon based on 
your comments.

Phillip

Thanks,
Stefan








